using System;
using System.IO;
using System.Collections;
using Lucene.Net.Analysis;

namespace Lucene.Net.Analysis.CJK
{
	/* ====================================================================
	 * The Apache Software License, Version 1.1
	 *
	 * Copyright (c) 2004 The Apache Software Foundation.  All rights
	 * reserved.
	 *
	 * Redistribution and use in source and binary forms, with or without
	 * modification, are permitted provided that the following conditions
	 * are met:
	 *
	 * 1. Redistributions of source code must retain the above copyright
	 *    notice, this list of conditions and the following disclaimer.
	 *
	 * 2. Redistributions in binary form must reproduce the above copyright
	 *    notice, this list of conditions and the following disclaimer in
	 *    the documentation and/or other materials provided with the
	 *    distribution.
	 *
	 * 3. The end-user documentation included with the redistribution,
	 *    if any, must include the following acknowledgment:
	 *       "This product includes software developed by the
	 *        Apache Software Foundation (http://www.apache.org/)."
	 *    Alternately, this acknowledgment may appear in the software itself,
	 *    if and wherever such third-party acknowledgments normally appear.
	 *
	 * 4. The names "Apache" and "Apache Software Foundation" and
	 *    "Apache Lucene" must not be used to endorse or promote products
	 *    derived from this software without prior written permission. For
	 *    written permission, please contact apache@apache.org.
	 *
	 * 5. Products derived from this software may not be called "Apache",
	 *    "Apache Lucene", nor may "Apache" appear in their name, without
	 *    prior written permission of the Apache Software Foundation.
	 *
	 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
	 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
	 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
	 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
	 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
	 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
	 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
	 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
	 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	 * SUCH DAMAGE.
	 * ====================================================================
	 *
	 * This software consists of voluntary contributions made by many
	 * individuals on behalf of the Apache Software Foundation.  For more
	 * information on the Apache Software Foundation, please see
	 * <http://www.apache.org/>.
	 *
	 * $Id: CJKAnalyzer.java,v 1.2 2004/01/22 20:54:47 ehatcher Exp $
	 */

	/// <summary>
	/// Filters CJKTokenizer with StopFilter.
	/// 
	/// @author Che, Dong
	/// </summary>
	public class CJKAnalyzer : Analyzer 
	{
		//~ Static fields/initializers ---------------------------------------------

		/**
		  * An array containing some common English words that are not usually
		  * useful for searching. and some double-byte interpunctions.....
		  */
		private static String[] stopWords = 
		{
			"a", "and", "are", "as", "at", "be",
			"but", "by", "for", "if", "in",
			"into", "is", "it", "no", "not",
			"of", "on", "or", "s", "such", "t",
			"that", "the", "their", "then",
			"there", "these", "they", "this",
			"to", "was", "will", "with", 
			"www"
		};

		//~ Instance fields --------------------------------------------------------

		/** stop word list */
		private Hashtable stopTable;

		//~ Constructors -----------------------------------------------------------

		/// <summary>
		/// Builds an analyzer which removes words in STOP_WORDS.
		/// </summary>
		public CJKAnalyzer() 
		{
            stopTable = StopFilter.MakeStopSet(stopWords);
		}

		/// <summary>
		/// Builds an analyzer which removes words in the provided array.
		/// </summary>
		/// <param name="stopWords">stop word array</param>
		public CJKAnalyzer(String[] stopWords) 
		{
            stopTable = StopFilter.MakeStopSet(stopWords);
		}

		//~ Methods ----------------------------------------------------------------

		/// <summary>
		/// get token stream from input
		/// </summary>
		/// <param name="fieldName">lucene field name</param>
		/// <param name="reader">input reader</param>
		/// <returns>Token Stream</returns>
		public override sealed TokenStream TokenStream(String fieldName, TextReader reader) 
		{
			return new StopFilter(new CJKTokenizer(reader), stopTable);
		}
	}
}
